Two minor nits on top of the review:

On 07/06/2023 14:54, Konrad Dybcio wrote:

On 7.06.2023 12:56, Varadarajan Narayanan wrote:

quoted

Add the M31 USB2 phy driver

Signed-off-by: Varadarajan Narayanan <redacted>
---
  drivers/phy/qualcomm/phy-qcom-m31.c | 360 ++++++++++++++++++++++++++++++++++++
  1 file changed, 360 insertions(+)
  create mode 100644 drivers/phy/qualcomm/phy-qcom-m31.c

diff --git a/drivers/phy/qualcomm/phy-qcom-m31.c b/drivers/phy/qualcomm/phy-qcom-m31.c
new file mode 100644
index 0000000..d29a91e
--- /dev/null
+++ b/drivers/phy/qualcomm/phy-qcom-m31.c

@@ -0,0 +1,360 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2014-2016, 2020, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/usb/phy.h>
+#include <linux/reset.h>
+#include <linux/of_device.h>

Please sort these

quoted

+
+enum clk_reset_action {
+	CLK_RESET_DEASSERT	= 0,
+	CLK_RESET_ASSERT	= 1
+};
+
+#define USB2PHY_PORT_POWERDOWN		0xA4
+#define POWER_UP			BIT(0)
+#define POWER_DOWN			0
+
+#define USB2PHY_PORT_UTMI_CTRL1	0x40
+
+#define USB2PHY_PORT_UTMI_CTRL2	0x44
+#define UTMI_ULPI_SEL			BIT(7)
+#define UTMI_TEST_MUX_SEL		BIT(6)
+
+#define HS_PHY_CTRL_REG			0x10
+#define UTMI_OTG_VBUS_VALID             BIT(20)
+#define SW_SESSVLD_SEL                  BIT(28)
+
+#define USB_PHY_CFG0			0x94
+#define USB_PHY_UTMI_CTRL5		0x50
+#define USB_PHY_FSEL_SEL		0xB8
+#define USB_PHY_HS_PHY_CTRL_COMMON0	0x54
+#define USB_PHY_REFCLK_CTRL		0xA0
+#define USB_PHY_HS_PHY_CTRL2		0x64
+#define USB_PHY_UTMI_CTRL0		0x3c
+#define USB2PHY_USB_PHY_M31_XCFGI_1	0xBC
+#define USB2PHY_USB_PHY_M31_XCFGI_4	0xC8
+#define USB2PHY_USB_PHY_M31_XCFGI_5	0xCC
+#define USB2PHY_USB_PHY_M31_XCFGI_11	0xE4

Could you sort them address-wise?

... and lowercase the hex values, please.

quoted

+
+#define USB2_0_TX_ENABLE		BIT(2)
+#define HSTX_SLEW_RATE_565PS		3
+#define PLL_CHARGING_PUMP_CURRENT_35UA	(3 << 3)
+#define ODT_VALUE_38_02_OHM		(3 << 6)
+#define ODT_VALUE_45_02_OHM		BIT(2)
+#define HSTX_PRE_EMPHASIS_LEVEL_0_55MA	(1)

Weird mix of values, bits, bitfields.. perhaps BIT(n) and
GENMASK() (+ FIELD_PREP) would be more suitable?

quoted

+
+#define UTMI_PHY_OVERRIDE_EN		BIT(1)
+#define POR_EN				BIT(1)

Please associate these with their registers, like

#define FOO_REG		0xf00
  #define POR_EN		BIT(1)

quoted

+#define FREQ_SEL			BIT(0)
+#define COMMONONN			BIT(7)
+#define FSEL				BIT(4)
+#define RETENABLEN			BIT(3)
+#define USB2_SUSPEND_N_SEL		BIT(3)
+#define USB2_SUSPEND_N			BIT(2)
+#define USB2_UTMI_CLK_EN		BIT(1)
+#define CLKCORE				BIT(1)
+#define ATERESET			~BIT(0)
+#define FREQ_24MHZ			(5 << 4)
+#define XCFG_COARSE_TUNE_NUM		(2 << 0)
+#define XCFG_FINE_TUNE_NUM		(1 << 3)

same comment

quoted

+
+static void m31usb_write_readback(void *base, u32 offset,
+					const u32 mask, u32 val);

We don't need this forward-definition, just move the function up.

quoted

+
+struct m31usb_phy {
+	struct usb_phy		phy;
+	void __iomem		*base;
+	void __iomem		*qscratch_base;
+
+	struct reset_control	*phy_reset;
+
+	bool			cable_connected;
+	bool			suspended;
+	bool			ulpi_mode;
+};
+
+static void m31usb_reset(struct m31usb_phy *qphy, u32 action)
+{
+	if (action == CLK_RESET_ASSERT)
+		reset_control_assert(qphy->phy_reset);
+	else
+		reset_control_deassert(qphy->phy_reset);
+	wmb(); /* ensure data is written to hw register */

Please move the comment above the call.

quoted

+}

Or even better just inline the function. I was never a fan of such 
multiplexers.

Also does wmb() make sense here? Doesn't regmap (which is used by reset 
controller) remove the need for it?

quoted

+
+static void m31usb_phy_enable_clock(struct m31usb_phy *qphy)
+{
+	/* Enable override ctrl */
+	writel(UTMI_PHY_OVERRIDE_EN, qphy->base + USB_PHY_CFG0);

Some of the comments are missing a space before '*/'

Also, please consider adding some newlines to logically split the
actions.

-- 
With best wishes
Dmitry


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